I was reading through my summer review book. Japanese Sentence Patterns for Effective Communication and I ran into the pattern ta form+tokoro da/desu to indicate something has just happened. In the following sentences how is it different from te-shimaimashita. Te-shimau wa explained to me as an action you just finished or completed, sometimes regretting it.

Friend calls you on the phone, notices you sound groggy or whatever so he asks are you ok and you respond?
(I just woke up)
Ima, okite shimaismashita
Ima, okita tokoro desu

You Look very sick, So a friend inquires about your condition and you respond
(I just ate a spoiled octopus)

The big point is the regret, so 食べてしまった in this case is OK, but 起きてしまった is weird, unless you were suddenly awoken by something unpleasant.

台無し however doesn't mean spoiled in the sense of food going off, but rather something being spoiled or wasted, like a plan or an opportunity. 腐る(くさる) is the verb to use for spoiled food, but in the case of food poisoning etc. We usually sayあたる. So maybe タコにあたってしまった。We also have the noun 食中り(しょくあたり)=food poisoning.

becki_kanou wrote:The big point is the regret, so 食べてしまった in this case is OK, but 起きてしまった is weird, unless you were suddenly awoken by something unpleasant.

台無し however doesn't mean spoiled in the sense of food going off, but rather something being spoiled or wasted, like a plan or an opportunity. 腐る(くさる) is the verb to use for spoiled food, but in the case of food poisoning etc. We usually sayあたる. So maybe タコにあたってしまった。We also have the noun 食中り(しょくあたり)=food poisoning.

Firstly, Thanks for the response

Next, Thanks for the clarification on spoiled my dictionary gives one-word definitions and no example sentences so I picked the first one I saw.(I know bad dictionary, bad me)

In the first example if the phone call was the unpleasent thing that woke you up at about 4 in the morning would okite shimaimashita then be an appropriate response?